
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Microsoft YaHei', sans-serif;
        }
        
        body {
            background-color: #f0f2f5;
            color: #333;
            min-height: 100vh;
            overflow: hidden;
        }
        
        .container {
            display: flex;
            min-height: 100vh;
        }
        
        /* 侧边栏样式 - 三个大按钮 */
        .sidebar {
            width: 240px;
            background: linear-gradient(135deg, #1a3a5f, #2c5282);
            color: white;
            box-shadow: 2px 0 10px rgba(0, 0, 0, 0.1);
            display: flex;
            flex-direction: column;
            position: relative;
            z-index: 10;
        }
        
        .logo {
            display: flex;
            align-items: center;
            padding: 20px;
            border-bottom: 1px solid rgba(255, 255, 255, 0.1);
        }
        
        .logo i {
            font-size: 28px;
            margin-right: 12px;
            color: #4caf50;
        }
        
        .logo h1 {
            font-size: 22px;
            font-weight: 600;
        }
        
        .menu {
            display: flex;
            flex-direction: column;
            flex: 1;
            padding: 20px 0;
        }
        
        .menu-item {
            flex: 1;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            padding: 20px;
            cursor: pointer;
            transition: all 0.4s;
            position: relative;
            overflow: hidden;
            border-bottom: 1px solid rgba(255, 255, 255, 0.1);
        }
        
        .menu-item:last-child {
            border-bottom: none;
        }
        
        .menu-item:hover {
            background: rgba(255, 255, 255, 0.1);
        }
        
        .menu-item.active {
            background: rgba(255, 255, 255, 0.15);
        }
        
        .menu-item i {
            font-size: 42px;
            margin-bottom: 20px;
            transition: transform 0.3s;
        }
        
        .menu-item:hover i {
            transform: scale(1.1);
        }
        
        .menu-item span {
            font-size: 20px;
            font-weight: 500;
            text-align: center;
        }
        
        .sub-menu {
            position: absolute;
            left: 100%;
            top: 0;
            width: 200px;
            height: 100%;
            background: #fff;
            box-shadow: -5px 0 15px rgba(0, 0, 0, 0.1);
            transition: transform 0.3s ease;
            transform: translateX(100%);
            z-index: 100;
            padding: 20px 0;
            display: flex;
            flex-direction: column;
        }
        
        .sub-menu.active {
            transform: translateX(0);
        }
        
        .sub-item {
            padding: 18px 25px;
            cursor: pointer;
            transition: all 0.2s;
            font-size: 17px;
            color: #333;
            display: flex;
            align-items: center;
            position: relative;
        }
        
        .sub-item i {
            margin-right: 15px;
            font-size: 20px;
            color: #4caf50;
        }
        
        .sub-item:hover, .sub-item.active {
            background: #f5f9ff;
            color: #2c5282;
        }
        
        .sub-item.active::after {
            content: '';
            position: absolute;
            left: 0;
            top: 0;
            height: 100%;
            width: 4px;
            background: #4caf50;
        }
        
        /* 主内容区样式 */
        .main-content {
            flex: 1;
            padding: 20px;
            overflow-y: auto;
            position: relative;
        }
        
        .header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 25px;
            padding-bottom: 15px;
            border-bottom: 1px solid #eaeaea;
        }
        
        .header h2 {
            color: #2c5282;
            font-size: 24px;
            font-weight: 600;
            display: flex;
            align-items: center;
        }
        
        .header h2 i {
            margin-right: 12px;
            color: #4caf50;
        }
        
        .user-info {
            display: flex;
            align-items: center;
        }
        
        .user-avatar {
            width: 40px;
            height: 40px;
            border-radius: 50%;
            background-color: #4caf50;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-weight: bold;
            margin-right: 12px;
        }
        
        /* 卡片样式 */
        .card {
            background: white;
            border-radius: 8px;
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
            margin-bottom: 25px;
            overflow: hidden;
        }
        
        .card-header {
            padding: 18px 25px;
            background: linear-gradient(to right, #f8f9fa, #e9ecef);
            border-bottom: 1px solid #eaeaea;
            font-weight: 600;
            color: #2c5282;
            display: flex;
            align-items: center;
        }
        
        .card-header i {
            margin-right: 10px;
            color: #4caf50;
        }
        
        .card-body {
            padding: 25px;
        }
        
        /* 表格样式 */
        .table-container {
            overflow-x: auto;
        }
        
        table {
            width: 100%;
            border-collapse: collapse;
            min-width: 800px;
        }
        
        th {
            background-color: #f8f9fa;
            padding: 16px 15px;
            text-align: left;
            font-weight: 600;
            color: #2c5282;
            border-bottom: 2px solid #eaeaea;
        }
        
        td {
            padding: 14px 15px;
            border-bottom: 1px solid #eee;
            color: #555;
        }
        
        tr:hover td {
            background-color: #f5f9ff;
        }
        
        .action-btn {
            padding: 6px 12px;
            border-radius: 4px;
            background-color: #e3f2fd;
            color: #1976d2;
            border: none;
            cursor: pointer;
            transition: all 0.2s;
            font-size: 13px;
            margin-right: 5px;
        }
        
        .action-btn:hover {
            background-color: #bbdefb;
        }
        
        .action-btn.delete {
            background-color: #ffebee;
            color: #d32f2f;
        }
        
        .action-btn.delete:hover {
            background-color: #ffcdd2;
        }
        
        /* 响应式设计 */
        @media (max-width: 768px) {
            .container {
                flex-direction: column;
            }
            
            .sidebar {
                width: 100%;
                height: auto;
                flex-direction: row;
                flex-wrap: wrap;
            }
            
            .menu {
                flex-direction: row;
                flex-wrap: wrap;
            }
            
            .menu-item {
                flex: 1 0 33.33%;
                min-width: 200px;
            }
            
            .sub-menu {
                width: 100%;
                left: 0;
                top: 100%;
                height: auto;
                transform: translateY(100%);
            }
            
            .sub-menu.active {
                transform: translateY(0);
            }
        }
        
        /* 欢迎面板 */
        .welcome-panel {
            text-align: center;
            padding: 60px 20px;
            max-width: 800px;
            margin: 50px auto;
        }
        
        .welcome-panel h1 {
            font-size: 42px;
            color: #2c5282;
            margin-bottom: 20px;
        }
        
        .welcome-panel p {
            font-size: 18px;
            color: #555;
            line-height: 1.8;
            margin-bottom: 40px;
        }
        
        .stats-container {
            display: flex;
            justify-content: center;
            gap: 30px;
            margin-top: 50px;
        }
        
        .stat-card {
            background: white;
            border-radius: 10px;
            padding: 25px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
            width: 200px;
            text-align: center;
        }
        
        .stat-card i {
            font-size: 36px;
            color: #4caf50;
            margin-bottom: 15px;
        }
        
        .stat-card .number {
            font-size: 32px;
            font-weight: bold;
            color: #2c5282;
        }
        
        .stat-card .label {
            font-size: 16px;
            color: #777;
            margin-top: 5px;
        }